Padlocks in which a pair of locking members are slideably mounted for reciprocable movement into and out of notches in the heel and toe portions of the shackle are well known in the art. U.S. Pat. No. 3,475,930 describes such a padlock wherein the locking members are plates or slides respectively disposed in two different planes. U.S. Pat. No. 3,979,931 describes a padlock of this general type wherein the locking plates are respectively slideable in the same plane. In order to improve the safety factor of these latter type padlocks it would be desirable to incorporate means within the lock to prevent the intrusion of burglar tools into the lock mechanism physically to press the locking plates out of the locking positions. In addition, it would be desirable to reduce the manufacturing cost of the padlock. The present invention enables the manufacture of a laminated padlock at a reduced cost while enhancing the safety factor of the padlock by making it more difficult to pick.